1. 1Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands
2. 2Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands
3. 3Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands
4. 4Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands
5. 5Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands
6. 6Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, P.O. Box 20151, 1000 HD Amsterdam, The Netherlands